<div>
    Jenkins node label to bind.
    If left blank, one will be generated for you,
    and inside the step it will be bound to the variable <code>POD_LABEL</code>
    so you can use this as the argument to the <code>node</code> step.<br/>

    Example:
    <pre>
        podTemplate(...) {
            node(POD_LABEL) {
                // some steps
            }
        }
    </pre>
</div>
